Maintenance crews and automotive assembly plants and other manufacturing operations have a long felt need for more safety equipment in order to electrically and/or pneumatically shut off equipment that they are working on. The men and women performing the maintenance need to make sure that neither the electricity nor the pneumatics are operational on the machine which they are maintaining. Prior art methods of shutting off electricity have included walking over to the electrical control panel and turning off all the electricity to a particular part of the room in which the maintenance is being performed, or if wired properly, shutting off the electrical circuits to the machine being worked on. Many times these control panels are not in sight of the maintenance workers. Needless to say, third parties who do not know about the maintenance operation can turn the electricity back on without the knowledge of the maintenance crew, yielding an unsafe situation. As can be imagined, maintenance crew workers would have more confidence in their safety if they knew that they had the control and only they could turn off the electrical circuits that were shut off to the area in which they are working, and that there was not an ability for a third person to turn the electricity back on. The maintenance crew needs to know that both the electrical system and the pneumatic system have been shut off in the case of lifter machines and other equipment which utilize both electrical and pneumatic devices.
Moreover, maintenance crews are subject to placing themselves in danger to save a little time by turning off the electricity within a certain area, and then returning to attempt to only turn on the electricity to a certain portion, while still being within the area of danger. It is necessary for the electricity to be shut off to the entire area in order for a maintenance person to perform his or her task in a totally safe manner. The temptation may always be there for trying to partially operate a machine while hoping that they do not get caught in the mechanics of another portion which should be shut off. In normal assembly plants, there are work cell safety gates which separate various machines in order to create safety zones, and it would be most prudent if the electrical and pneumatic shut off could occur even at the gate entering the safety zone which incorporates the manufacturing equipment. For instance, a gate entering into a lifting machine could have all the electricity shut off the minute that the gate is opened up. Furthermore, safety lock-out devices could be utilized on the lifter to render the pneumatics immobile, thereby giving the maintenance person a green light to perform their expected duties.
OSHA regulations have attempted to provide safety mechanisms for the maintenance crews in order to reduce injuries and down time. Many times, maintenance crews and machine operators have figured out how to electrically "jumper", tamper, override or bypass the safety equipment. This has resulted in numerous injuries and expense to companies for repairs. It would be most desirable to have a failsafe system for rendering the machine within a gated area to be non-operational during the maintenance period.
Therefore, it would be an advantage to the art to provide an electrical and pneumatic lock-out device for rendering machines completely free of the possibility of them being turned on or moved while the maintenance person is performing his or her tasks.
It would be yet a further advantage to provide a complete electrical and pneumatic lock-out device which cannot be manually overridden or bypassed.